What type of signal can be represented by a sine wave?

A sine wave is a fundamental waveform that represents the most common type of alternating current (AC) signal. In AC circuits, the voltage or current varies sinusoidally with time, oscillating between positive and negative values. This oscillation is characterized by its amplitude, frequency, and phase.

The sine wave is pivotal because it describes the behavior of AC systems, which are widely used in power generation and distribution. The smooth and continuous nature of a sine wave allows for the efficient transmission of electrical power over long distances. Additionally, most electrical devices and systems are designed to operate with AC, leveraging its characteristics for various applications.

In contrast, other types of signals such as direct current (DC) maintain a constant value over time, square waves alternate between high and low states with abrupt changes, and pulsed DC involves rapid pulsing that isn’t smooth like a sine wave. Thus, the sine wave’s unique properties make it specifically representative of alternating current.